linux-toradex.git/Documentation/networking, branch v3.13-rc8

ipv4: improve documentation of ip_no_pmtu_disc

2013-12-17T20:20:15+00:00

Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

packet: fix send path when running with proto == 0

2013-12-10T01:09:20+00:00

Commit e40526cb20b5 introduced a cached dev pointer, that gets
hooked into register_prot_hook(), __unregister_prot_hook() to
update the device used for the send path.

We need to fix this up, as otherwise this will not work with
sockets created with protocol = 0, plus with sll_protocol = 0
passed via sockaddr_ll when doing the bind.

So instead, assign the pointer directly. The compiler can inline
these helper functions automagically.

While at it, also assume the cached dev fast-path as likely(),
and document this variant of socket creation as it seems it is
not widely used (seems not even the author of TX_RING was aware
of that in his reference example [1]). Tested with reproducer
from e40526cb20b5.

 [1] http://wiki.ipxwarzone.com/index.php5?title=Linux_packet_mmap#Example

Fixes: e40526cb20b5 ("packet: fix use after free race in send path when dev is released")
Signed-off-by: Daniel Borkmann 
Tested-by: Salam Noureddine 
Tested-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller

tcp: tsq: restore minimal amount of queueing

2013-11-14T21:25:14+00:00

After commit c9eeec26e32e ("tcp: TSQ can use a dynamic limit"), several
users reported throughput regressions, notably on mvneta and wifi
adapters.

802.11 AMPDU requires a fair amount of queueing to be effective.

This patch partially reverts the change done in tcp_write_xmit()
so that the minimal amount is sysctl_tcp_limit_output_bytes.

It also remove the use of this sysctl while building skb stored
in write queue, as TSO autosizing does the right thing anyway.

Users with well behaving NICS and correct qdisc (like sch_fq),
can then lower the default sysctl_tcp_limit_output_bytes value from
128KB to 8KB.

This new usage of sysctl_tcp_limit_output_bytes permits each driver
authors to check how their driver performs when/if the value is set
to a minimum of 4KB.

Normally, line rate for a single TCP flow should be possible,
but some drivers rely on timers to perform TX completion and
too long TX completion delays prevent reaching full throughput.

Fixes: c9eeec26e32e ("tcp: TSQ can use a dynamic limit")
Signed-off-by: Eric Dumazet 
Reported-by: Sujith Manoharan 
Reported-by: Arnaud Ebalard 
Tested-by: Sujith Manoharan 
Cc: Felix Fietkau 
Signed-off-by: David S. Miller

bonding: document the new packets_per_slave option

2013-11-07T20:10:21+00:00

Add new documentation for the packets_per_slave option available
for balance-rr mode.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

Merge branch 'for-davem' of git://gitorious.org/linux-can/linux-can-next

2013-11-05T00:59:44+00:00

Marc Kleine-Budde says:

====================
here's a pull request for net-next.

It includes a patch by Oliver Hartkopp et al. that adds documentation
for the broadcast manager to Documentation/networking/can.txt. Three
patches by me that clean up the netlink handling code in the CAN core.
And another patch that removes a not needed function from the ti_hecc
driver.
====================

Signed-off-by: David S. Miller

tcp: properly handle stretch acks in slow start

2013-11-05T00:57:59+00:00

Slow start now increases cwnd by 1 if an ACK acknowledges some packets,
regardless the number of packets. Consequently slow start performance
is highly dependent on the degree of the stretch ACKs caused by
receiver or network ACK compression mechanisms (e.g., delayed-ACK,
GRO, etc).  But slow start algorithm is to send twice the amount of
packets of packets left so it should process a stretch ACK of degree
N as if N ACKs of degree 1, then exits when cwnd exceeds ssthresh. A
follow up patch will use the remainder of the N (if greater than 1)
to adjust cwnd in the congestion avoidance phase.

In addition this patch retires the experimental limited slow start
(LSS) feature. LSS has multiple drawbacks but questionable benefit. The
fractional cwnd increase in LSS requires a loop in slow start even
though it's rarely used. Configuring such an increase step via a global
sysctl on different BDPS seems hard. Finally and most importantly the
slow start overshoot concern is now better covered by the Hybrid slow
start (hystart) enabled by default.

Signed-off-by: Yuchung Cheng 
Signed-off-by: Neal Cardwell 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

tcp: enable sockets to use MSG_FASTOPEN by default

2013-11-05T00:57:47+00:00

Applications have started to use Fast Open (e.g., Chrome browser has
such an optional flag) and the feature has gone through several
generations of kernels since 3.7 with many real network tests. It's
time to enable this flag by default for applications to test more
conveniently and extensively.

Signed-off-by: Yuchung Cheng 
Signed-off-by: Neal Cardwell 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2013-11-04T18:48:30+00:00

Conflicts:
	drivers/net/ethernet/emulex/benet/be.h
	drivers/net/netconsole.c
	net/bridge/br_private.h

Three mostly trivial conflicts.

The net/bridge/br_private.h conflict was a function signature (argument
addition) change overlapping with the extern removals from Joe Perches.

In drivers/net/netconsole.c we had one change adjusting a printk message
whilst another changed "printk(KERN_INFO" into "pr_info(".

Lastly, the emulex change was a new inline function addition overlapping
with Joe Perches's extern removals.

Signed-off-by: David S. Miller

net: extend net_device allocation to vmalloc()

2013-11-04T04:19:00+00:00

Joby Poriyath provided a xen-netback patch to reduce the size of
xenvif structure as some netdev allocation could fail under
memory pressure/fragmentation.

This patch is handling the problem at the core level, allowing
any netdev structures to use vmalloc() if kmalloc() failed.

As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT
to kzalloc() flags to do this fallback only when really needed.

Signed-off-by: Eric Dumazet 
Reported-by: Joby Poriyath 
Cc: Ben Hutchings 
Signed-off-by: David S. Miller

can: add broadcast manager documentation

2013-10-31T19:45:04+00:00

This patch adds documentation about the broadcast manager. It's based on Brian
Thorne's initial patch http://marc.info/?l=linux-can&m=138119382015496&w=2 and
Daniele Venzano's work http://brownhat.org/docs/socketcan.html .

Signed-off-by: Brian Thorne 
Cc: Daniele Venzano 
Cc: Andre Naujoks 
Signed-off-by: Oliver Hartkopp 
Signed-off-by: Marc Kleine-Budde